If and are integers (with not zero), we say divides
if there is an integer such that .
we write, means divides .
are positive integers such that
Find the least possible value of
we see that
Thus we may write for some integer
This shows that and hence .
We therefore obtain
It follows that
Taking a = 23 and b = 5
we see that the conditions of the problem satisfied.
Thus the minimum value of a + b is 28